Antenna structure



FIG. 1 is a perspective view of a first embodiment of an antenna structure showing our new design;

FIG. 2 is an inverted rear elevational view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a left side elevational view thereof;

FIG. 7 is a right side elevational view thereof;

FIG. 8 is a perspective view of a second embodiment of an antenna structure;

FIG. 9 is an inverted rear elevational view thereof;

FIG. 10 is a top plan view thereof;

FIG. 11 is a front elevational view thereof;

FIG. 12 is a bottom plan view thereof;

FIG. 13 is a left side elevational view thereof; and,

FIG. 14 is a right side elevational view thereof.

The broken lines illustrate environmental structure and form no part of the claimed design. 

The ornamental design for an antenna structure, as shown and described. 